1. Technical Field
The present invention relates to a semiconductor device and a manufacturing method of the same.
2. Related Art
A semiconductor device (semiconductor element) is required to reduce the potential crowding that occurs in the peripheries of a semiconductor layer and an electrode and thereby reduce the reverse leakage current. Especially in a semiconductor device used as power device, it is important to reduce the potential crowding and thereby reduce the reverse leakage current, in order to improve the breakdown voltage.
Patent Literatures 1 and 2 respectively describe a technique that reduces the potential crowding occurring at an end of a Schottky electrode in a Schottky diode by using a field plate structure. Patent Literature 3 describes a field plate structure provided by a nitride insulating layer having a positive fixed charge density lower than 1.2×1012 cm−2 at an interface with a semiconductor layer in a gallium nitride-based Schottky diode.
Non-Patent Literature 1 describes a technique that reduces the potential crowding occurring at an end of a pn junction that is exposed on a side face of an element isolation structure formed by dry etching, by using a field plate structure.
Patent Literature 4 describes a technique that injects negatively charged particles into an insulating film that is formed to cover the surface of a p-type semiconductor layer exposed by dry etching, in a group III nitride-based semiconductor device, in order to prevent a change from the surface of the p-type semiconductor layer to an n-type.